EP0144599B1 - Support de bande pneumatique pour guider la bande et pour détecter la tension de bande - Google Patents

Support de bande pneumatique pour guider la bande et pour détecter la tension de bande Download PDF

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Publication number
EP0144599B1
EP0144599B1 EP19840111873 EP84111873A EP0144599B1 EP 0144599 B1 EP0144599 B1 EP 0144599B1 EP 19840111873 EP19840111873 EP 19840111873 EP 84111873 A EP84111873 A EP 84111873A EP 0144599 B1 EP0144599 B1 EP 0144599B1
Authority
EP
European Patent Office
Prior art keywords
tape
port
arcuate surface
reel
semidisk
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19840111873
Other languages
German (de)
English (en)
Other versions
EP0144599A2 (fr
EP0144599A3 (en
Inventor
Bernard Lowell Callender
William Wai-Chung Chow
Thomas George Osterday
William John Rueger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0144599A2 publication Critical patent/EP0144599A2/fr
Publication of EP0144599A3 publication Critical patent/EP0144599A3/en
Application granted granted Critical
Publication of EP0144599B1 publication Critical patent/EP0144599B1/fr
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
    • G11B15/43—Control or regulation of mechanical tension of record carrier, e.g. tape tension
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/60—Guiding record carrier
    • G11B15/605—Guiding record carrier without displacing the guiding means
    • G11B15/607—Pneumatic guiding
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/60—Guiding record carrier
    • G11B15/62—Maintaining desired spacing between record carrier and head
    • G11B15/64—Maintaining desired spacing between record carrier and head by fluid-dynamic spacing

Definitions

  • This invention relates to an air bearing tape support in a tape drive which is capable of simultaneously guiding the tape over a tape path while sensing tape tension.
  • Magnetic tape As a data storage medium.
  • the magnetic tape is wound and rewound between reels in a reel-to-reel tape drive and guided past a read-write head by bearings which provide an interface of forced air with the magnetic tape to lower friction forces between the tape and bearing surface and which permit rapid acceleration and deceleration of the magnetic tape. Since information is stored on the magnetic tape in a very dense format, it is necessary that the tape path be accurately controlled so as to provide accurate data writing and reading.
  • Three functions that a reel-to-reel tape drive must provide are: sensing tension in the tape; buffering or decoupling the tape at the magnetic head from any perturbations arising at the reels; and, reliably guiding the tape along the tape path.
  • a separate station is required to accomplish each of these three functions. That is, a first apparatus senses tape tension, a second apparatus decouples the tape at the head from any perturbations arising at the reels, and a third apparatus guides the tape along the tape path. It would be most desirable in a reel-to-reel tape drive to have one station perform all of the these three required functions.
  • the first problem arises when contaminants clog the sense port so that the pressure between tape and arcuate surface cannot be determined.
  • the second problem arises as a result of vibratory movement of the tape across the arcuate surface.
  • tape vibrations occur, the distance between tape and sense port can change dramatically with an attendant loss in accuracy of pressure and hence tension measured.
  • the vibrating tape can come in contact with the sense port shutting it off and thus rendering the sense port useless as a pressure measuring device.
  • the vibrations are induced by disturbances which are generated at the take-up reel in the tape drive. Tape vibration has a frequency of 100 cycles per second or higher whereas disturbance is irregular and has a frequency below 100 cycles per second.
  • a pressure measuring transducer having the ability to measure tape tension in the presence of contaminants. It would also be desirable to control tape vibratory motion by preventing disturbances at the take-up reel from inducing vibrations at the arcuate surface of the pressure transducer. This would enable more accurate measurement of the pressure existing between the moving tape and the arcuate surface around which the tape is passed.
  • a purging means is provided for clearing a sense port of contaminants.
  • a guiding flange is provided which positively guides the tape in the tape drive while greatly reducing the vibratory motion of the tape.
  • Another object of this invention is to provide a reel-to-reel tape drive wherein the functions of guiding, decoupling, and tension sensing are accomplished using a single tape drive station and still another object is to provide a reel-to-reel tape drive wherein a guiding flange provides positive guiding of the tape while simultaneously decoupling the tape from the tape reels so as to maintain tape vibration.
  • the present invention relates to a tape support in a reel-to-reel tape drive which provides guiding of the tape, sensing of tape tension, and disturbance decoupling between the take-up reel and bearings which guide the tape over the read-write head.
  • This tape support is connected to a solid state sensing transducer which is able to determine tape tension from the pressure measured between the tape and the surface of the tape support around which the tape passes.
  • a port in the surface of the tape support around which the tape passes is used to sense the pressure between the tape and the surface of the tape support.
  • a sense line is connected between the port and the solid state sensing transducer. This sense line communicates the pressure measured at the port to the solid state sensing transducer. There is no air flow in this sense line.
  • the compacting of air molecules within the sense line reflects the pressure sensed at the port. The compaction of air molecules provides to the solid state sensing transducer a measure of the pressure sensed at the port.
  • a purge line is located at the port end of the sense line. This purge lines provides a continuous air flow out of the sense line.
  • the tape support has a plenum through which air under pressure is directed. Apertures in the surface of the tape support allow this air to be directed over half of the surface of the tape support so as to provide an air cushion over which the tape passes.
  • This air cushion is known in the art as a hydrostatic air bearing, and the surface over which the tape passes is known as an air bearing surface. The air bearing surface extends only over half of the tape support.
  • the purge line is connected to the same source of pressured air which provides the air bearing.
  • the purge time will also be operational to clear contaminants from the sense port.
  • the continuous flow of air from the purge line out through the sense port reduces the possibility of the tape getting stuck on the sense port due to a vacuum in the sense line. If the tape were to become stuck on the sense port by a vacuum in the sense line, no more pressure sensing would be possible until the tape were removed form the sense port. If the tape seals the sense port for other reasons, such as high tape tension or sticking caused by friction, the purge line will increase pressure within the sense line to a maximum level. This increased pressure trips a tension error sensor in the solid state sensing transducer.
  • the tape support has a substantially cylindrical shape.
  • the tape is passed along the arcuate surface of this substantially cylindrical tape support.
  • Affixed to the top and bottom ends of the tape support are flanges which act to guide the tape.
  • Each of the flanges is composed of two semidisk-shaped halves which are joined together so as to form one disk-shaped member.
  • One half of the disk-shaped member has a thickness which is less than the thickness of the other half of the disk-shaped member.
  • the thinner section of the disk-shaped member is located on the half of the tape support which has the air bearing surface over which the tape passes.
  • the reduced thickness of the flanges on the air bearing side of the tape support forms vents so that the air from the apertures in the air bearing surface can escape and the edge of the tape will not be in contact with the flanges.
  • the vertical spacing between the top and bottom flanges on the air bearing side of the tape support is somewhat wider then the width of the tape.
  • the tape On the air bearing side of the tape support, the tape is free from vertical edge guiding. All vertical edge guiding occurs at the points where the flanges are thicker and the tape is not supported by an air bearing, i.e. where the two semidisk-shaped members are joined.
  • magnetic tape 11 is unwound from supply reel 19, traverses past read bearing 12, write bearing 13, magnetic head 14, decoupler column 15, tape support 16, and is wound onto take-up reel 18.
  • Tape support 16 has a sense port 17 for determining the pressure existing between tape 11 and tape support 16. The tension on magnetic tape 11 can then be determined based upon the pressure sensed.
  • take-up reel 18 and supply reel 19 change diameter as the tape drive 10 is operated. When supply reel 19 is first loaded into tape drive 10, it has a diameter represented by circle 44. At this time, take-up reel 18 has a diameter represented by circle 41. As the operation of tape drive 10 continues, supply reel 19 has a diameter represented by circle 45 and take-up reel 18 has a diameter represented by circle 42.
  • supply reel 19 has a diameter represented by circle 46 and take-up reel 18 has a diameter represented by circle 43.
  • circle 46 the diameter represented by circle 46
  • take-up reel 18 has a diameter represented by circle 43.
  • the wrap angle that tape 11 makes around tape support 16 is on the order of 180° with slight changes due to changes in reel diameter as heretofore explained. Having a wrap angle of this magnitude minimizes the influence of take-up reel 18 on tape 11 at read bearing 12. As a result, the possible vibrations of tape 11 at read bearing 12 induced by disturbances at take-up reel 18 are substantially reduced. The possible vibrations of tape 11 at write bearing 13 induced by disturbances at supply reel 19 are reduced by decoupler column 15.
  • the tension on tape 11 is equal to the pressure sensed by port 17 multiplied by the width of tape 11 multiplied by the air bearing radius.
  • the air bearing radius includes the radius of tape support 16 as well as the distance between the air bearing surface of the tape support 16 and the surface of tape 11. As can be seen from this relationship, the tension on tape 11 is directly proportional to the pressure sensed by sense port 17.
  • tape support 16 has a substantially cylindrical configuration.
  • Solid state sensing transducer 22 is inserted into a cavity in the bottom side of tape support 16.
  • Sense line 29 extends from silicon crystal 21 within transducer 22 into the body of tape support 16 and terminates at sense port 17.
  • Silicon crystal 21 produces an output proportional to the air pressure sensed at port 17.
  • Purge line 28 provides a flow of air out of sense port 17 thus preventing contaminants from clogging the opening of port 17. There is no air flow from purge line 28 down sense line 29 towards silicon crystal 21. The compacting of air molecules within sense line 29 reflects the pressure sensed at port 17.
  • solid state transducer 22 sense line 29, and sense port 17 is similar to a flapper valve. Tape 11 is analogous to the flapper while sense port 17 is analogous to the nozzle in a flapper valve. The major difference between a standard flapper valve and the operation detailed herein is that there is an air flow to solid state transducer 22.
  • solid state sensing transducer 22 is first calibrated putting a known amount of tension on tape 11.
  • Transducer 22 produces an output voltage which is proportional to the gain of transducer 22 multiplied by the air pressure measured at sense port 17, plus an offset voltage dependent upon the transducer 22.
  • the output voltage of transducer 22 will provide a direct indication of the pressure existing at sense port 17 and hence the tension on tape 11.
  • the output voltage of transducer 22 can be used to directly determine the tension on tape 11.
  • the values of the pressure sensed at port 17, the width of tape 11, and the radius of tape support 16 will all be subsumed in the output voltage of transducer 22.
  • it will only be necessary to measure the output voltage of transducer 22.
  • Arcuate surface 23 forms the air bearing surface over which tape 11 passes.
  • Small apertures 37 (Fig. 3a) in arcuate surface 23 allow air under pressure to be forced out through apertures 37 so as to provide an air cushion over which tape 11 travels.
  • Apertures 37 are located in only half of arcuate surface 23. This will be explained in greater detail with relation to Fig. 3a. The creation of such an air bearing surface is well known in the art and need not be detailed herein.
  • Purge line 28 is connected to the same supply of pressurized air which creates the air bearing surface. As long as an air bearing surface is created by the expelling of air through apertures 37 in arcuate surface 23, purge line 28 will be effective to force contaminants out of the opening of sense port 17. The air flowing out of sense port 17 will also prevent tape 11 from collapsing on port 17 due to a vacuum within sense line 29. Such a vacuum would prevent the operation of solid state tension transducer 22.
  • Flanges 24 are affixed to the top and bottom ends of tape support 16. A more detailed explanation of their structure will be presented in relation to Figs. 3a and 3b. Flanges 24 help guide tape 11 over arcuate surface 23. Without flanges 24, tape 11 would become skewed with respect to arcuate surface 23 and could under appropriate circumstances allow tape 11 to move away from sense port 17 so that the tension on tape 11 could not be measured.
  • flanges 24 each comprises a first semidisk-shaped member 34 as well as a second semidisk-shaped member 35 joined together. The thickness of members 34 is less than the thickness of members 35.
  • Apertures 37 and hence the air bearing are located in the half of arcuate surface 23 which is adjacent to the thinner sections of flanges 24, i.e., adjacent to members 34.
  • the reduced thickness of members 34 forms vents 38 between arcuate surface 23 and members 34. Vents 38 allow air from apertures 37 in arcuate surface 23 to escape and as a result prevent the edges of tape 11 from contacting members 34. This reduces edge wear on tape 11. As an additional aid to reducing edge wear on tape 11, the distance between members 34 is somewhat greater than the width of tape 11. Vents 38 also reduce disturbance induced vibration in tape 11.
  • leader block (not shown) which is wider than tape 11 and also wider than the distance between members 34.
  • the leader block facilitates load and unload operations. During load and unload operations, no air bearing exists in arcuate surface 23. Members 34 of flanges 24 prevent the leader blocks from crashing and/or dragging on the air bearing portion of arcuate surface 23.
  • any appropriate gaseous medium may be used to create a gaseous cushion over which the tape travels.

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  • Advancing Webs (AREA)

Claims (1)

  1. Mécanisme d'entraînement de bande comprenant un support de bande sensiblement cylindrique (16) ayant une surface courbe autour de laquelle on fait passer une bande (11), la surface courbe ayant une pluralité l'ouvertures au travers desquelles un gaz peut être fourni sous pression pour porter la bande sur un coussin gazeux, le mécanisme d'entraînement de bande comprenant:
    un accès (17) dans la surface courbe pour détecter la pression gazeuse entre la bande et la surface courbe,
    un transducteur de détection à semiconducteur (22) couplé opérativement à l'accès par l'intermédiaire d'une conduite de détection (29) s'étendant à partir de l'accès (17) jusqu'au transducteur de détection à semiconducteur (21) pour communiquer au transducteur de détection à semiconducteur la pression gazeuse détectée au niveau de l'accès,
    caractérisé par des moyens pour améliorer les conditions de détection de la pression au niveau de l'accès, comprenant:
    une ouverture supplémentaire (28) pour le gaz située dans la conduite de détection de façon adjacente à l'accès, de sorte que le gaz est expulsé hors de l'accès, mais que sensiblement aucun gaz ne s'écoule dans la conduite de détection (29), et
    des premier et deuxième flasques (24) fixés aux extrémités supérieure et inférieure, respectivement, du support de bande sensiblement cylindrique (16), les premier et deuxième flasques (24) comprenant chacun une première partie en forme de demi-disque (34) et une deuxième partie en forme de demi-disque (35) unie à la première partie en forme de demi-disque, formant ainsi un élément ayant sensiblement une forme de disque, la première partie en forme de demi-disque (34) ayant une épaisseur inférieure à l'épaisseur de la deuxième partie en forme de demi-disque (35), formant ainsi des évents (38) entre la première partie en forme de demi-disque et la surface courbe au travers desquels le gaz s'écoule.
EP19840111873 1983-12-02 1984-10-04 Support de bande pneumatique pour guider la bande et pour détecter la tension de bande Expired EP0144599B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US55757183A 1983-12-02 1983-12-02
US557571 2000-04-25

Publications (3)

Publication Number Publication Date
EP0144599A2 EP0144599A2 (fr) 1985-06-19
EP0144599A3 EP0144599A3 (en) 1987-02-04
EP0144599B1 true EP0144599B1 (fr) 1990-03-28

Family

ID=24225978

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19840111873 Expired EP0144599B1 (fr) 1983-12-02 1984-10-04 Support de bande pneumatique pour guider la bande et pour détecter la tension de bande

Country Status (3)

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EP (1) EP0144599B1 (fr)
JP (1) JPS60129961A (fr)
DE (1) DE3481791D1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2793410B2 (ja) * 1991-04-22 1998-09-03 インターナショナル・ビジネス・マシーンズ・コーポレイション ウェブ駆動装置及びテープ駆動装置
USD597951S1 (en) 2008-02-29 2009-08-11 Tyco Electronics Amp K.K. Electrical connector housing
USD583769S1 (en) 2008-02-29 2008-12-30 Tyco Electronics Amp K.K. Electrical connector
USD584693S1 (en) 2008-02-29 2009-01-13 Tyco Electronics Amp K.K. Electrical connector
USD581876S1 (en) 2008-02-29 2008-12-02 Tyco Electronics Amp K.K. Electrical connector

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1265042A (fr) * 1959-08-13 1961-06-23 Ampex Appareil à ruban magnétique
US3375963A (en) * 1964-10-27 1968-04-02 Ampex High performance tape transport
US4301687A (en) * 1980-05-19 1981-11-24 Computer Peripherals, Inc. Pneumatic tension sensor
JPS6093144U (ja) * 1983-11-28 1985-06-25 ソニー株式会社 テ−プガイド装置

Also Published As

Publication number Publication date
EP0144599A2 (fr) 1985-06-19
JPS60129961A (ja) 1985-07-11
EP0144599A3 (en) 1987-02-04
DE3481791D1 (de) 1990-05-03
JPH0312383B2 (fr) 1991-02-20

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